The proposed research and training plan aims to advance our understanding of risk markers for suicidal behavior in adolescents, and to equip the applicant with the skills necessary to carry out independent longitudinal research in the areas of developmental psychopathology and suicide. There is an urgent need to identify ways to reduce rates of suicide among adolescents, and an important first step is to establish risk markers - or predictors - of suicide in this age group. The goal of the proposed research is to identify multipl behavioral and biological (psychophysiological) risk markers for suicidal behavior in adolescents. Importantly, these goals are also consistent with the National Institute of Mental Health (NIMH) Strategic Plan, which highlights the need for identifying biological and behavioral markers associated with clinically relevant problems. This goal will be achieved through the following specific aims: Aim 1. To examine the relation between two behavioral tasks for suicide (i.e., death/suicide IAT and suicide Stroop test) and suicidal behavior in adolescents. Aim 2. To examine the relation between reduced fear responding during suicide-related stimuli (psychophysiological measure) and suicidal behavior in adolescents. Aim 3. To examine additive and interactive associations between behavioral and psychophysiological predictors of suicidal behavior in adolescents. This work has the potential to better identify those adolescents at greatest suicide risk, who are in critical need of intervention. In line with state f the art methods used to diagnose physical conditions, this line of research aims ultimately to identify a short battery of tests that can be used to objectively assess risk for suicide in adolescents. These measures are ideal because they are brief, easily administered and scored, and thus could feasibly be used in an emergency department or inpatient setting to inform decisions about adolescents' admission and discharge from hospital care. Therefore, this program of research has the potential to significantly advance clinical science and to modernize the way the field assesses risk for suicidal behavior. The training plan in this application extends the applicant's previous research and clinical experiences in the following areas: developmental psychopathology, suicide, and longitudinal research design and analysis. In order to achieve these goals, the applicant has carefully assembled a team of sponsors and consultants to guide and support this project. Dr. Matthew Nock (sponsor) has expertise in suicide research and adolescent psychopathology. Dr. Ronald Dahl (consultant) is an expert in adolescent brain and pubertal development, as well as in early interventions. Finally, Dr. Terry Blumenthal has expertise in the startle reflex methodology - the physiological measure chosen for this project. In sum, the F32 training will advance the applicant's knowledge and expertise in three new areas and provide the foundation for a career as an independent clinical scientist.